Figure 6.

Hematoxylin and eosin stain. Hematoxylin and eosin stain of patient repair tissue and healthy tissue with higher magnification of the superficial and deep zones of the articular cartilage. The superficial zone of the repair tissue contains a layer of fibrocartilage (blue bracket) that transitions to hyaline-like cartilage (red bracket) and then hyaline cartilage (black bracket), with some degenerative changes including chondrocyte clustering (red arrow) and fissuring (blue arrows). The deep zone contains hyaline cartilage (black bracket) with a replicated tidemark (black arrows). The healthy tissue is entirely hyaline cartilage with an established tidemark (black arrow) between the cartilage and the bone. Scale bars = 500 µm.